Information Notice No. 89-48:Design Deficiency in the Turbine-Driven Auxiliary Feedwater Pump Cooling Water System

                                  UNITED STATES
                          NUCLEAR REGULATORY COMMISSION
                             WASHINGTON, D.C.  20555

                                  May 22, 1989

Information Notice No. 89-48:  DESIGN DEFICIENCY IN THE TURBINE-
                                   DRIVEN AUXILIARY FEEDWATER PUMP 
                                   COOLING WATER SYSTEM


All holders of operating licenses or construction permits for nuclear power


This information notice is being provided to alert addressees to a design 
deficiency in a turbine-driven auxiliary feedwater pump cooling water system.  
It is expected that recipients will review the information for applicability 
to their facilities and consider actions, as appropriate, to avoid similar 
problems.  However, suggestions contained in this information notice do not 
constitute NRC requirements; therefore, no specific action or written response 
is required.

Description of Circumstances:

On April 13, 1989, the licensee for the Zion Station identified a design de-
ficiency in the turbine-driven auxiliary feedwater (AFW) pump cooling water 
system.  The deficiency was created when a modification was made to the 
turbine-driven AFW pump in order to satisfy the AC power independence criteri-
on.  This modification changed the pump's cooling water supply from the 
service water system to the auxiliary feedwater system.  The cooling water now 
comes from the fifth stage leakoff of the AFW pump and is supplied to the 
pump's lube oil cooler, the AFW turbine governor, and the AFW turbine bearings 
at 75 psig by a pressure-regulating valve.  The cooling water is then returned 
to the AFW pump suction line.  The deficiency would have occurred when the AFW 
pump suction was aligned to its emergency supply (service water) rather than 
its normal supply (the condensate storage tank).  In this emergency lineup, 
the suction pressure will increase to approximately 90 psig.  Because the AFW 
pump cooling water pressure would be below the AFW pump suction pressure, AFW 
pump cooling water flow would be lost.  This loss of cooling water flow could 
eventually lead to overheating of the AFW pump turbine bearings and failure of 
the AFW pump turbine.

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                                                                 May 22, 1989
                                                                 Page 2 of 2


The licensee made a temporary modification in the AFW pump cooling water 
return line configuration to correct this design deficiency.  A permanent 
modification is under development for future installation.

No specific action or written response is required by this information notice.   
If you have any questions about this matter, please contact the technical 
contact listed below or the Regional Administrator of the appropriate regional

                                   Charles E. Rossi, Director
                                   Division of Operational Events Assessment
                                   Office of Nuclear Reactor Regulation

Technical Contact:  Jared Wermiel, NRR
                    (301) 492-0870 

Attachment:  List of Recently Issued NRC Information Notices
..                                                            Attachment 
                                                            IN 89-48
                                                            May 22, 1989
                                                            Page 1 of 1

                             LIST OF RECENTLY ISSUED
                             NRC INFORMATION NOTICES
Information                                  Date of 
Notice No._____Subject_______________________Issuance_______Issued to________

89-47          Potential Problems With       5/18/89        All holders of OLs
               Worn or Distorted Hose                       or CPs for nuclear
               Clamps on Self-Contained                     power reactors and
               Breathing Apparatus                          fuel facilities.

89-46          Confidentiality of            5/11/89        All holders of 
               Exercise Scenarios                           licenses for fuel 
                                                            cycle facilities 
                                                            and byproduct 
                                                            material licensees 
                                                            having an approved 
                                                            emergency response 

89-45          Metalclad, Low-Voltage        5/8/89         All holders of OLs
               Power Circuit Breakers                       or CPs for nuclear
               Refurbished with Sub-                        power reactors.
               standard Parts

89-44          Hydrogen Storage on the       4/27/89        All holders of OLs
               Roof of the Control Room                     or CPs for nuclear
                                                            power reactors.

88-82,         Torus Shells with Corrosion   5/2/89         All holders of OLs
Supp. 1        and Degraded Coatings in                     or CPs for BWRs.
               BWR Containments

89-43          Permanent Deformation of      5/1/89         All holders of OLs
               Torque Switch Helical                        or CPs for nuclear
               Springs in Limitorque                        power reactors.
               SMA-Type Motor Operators

88-97,         Potentially Substandard       4/28/89        All holders of OLs
Supp. 1        Valve Replacement Parts                      or CPs for nuclear
                                                            power reactors.

89-42          Failure of Rosemount          4/21/89        All holders of OLs
               Models 1153 and 1154                         or CPs for nuclear
               Transmitters                                 power reactors.

89-41          Operator Response to          4/20/89        All holders of OLs
               Pressurization of Low-                       or CPs for nuclear
               Pressure Interfacing                         power reactors.
OL = Operating License
CP = Construction Permit 

Page Last Reviewed/Updated Friday, May 22, 2015